A Maine rehabilitation center where Michael Skakel stayed as a teen had an atmosphere of "intimidation" and "humiliation" that could have coerced a person to say things that might not be true, an expert witness testified Monday at a hearing in Skakel's latest bid for freedom.

Richard Ofshe, a social psychologist who has studied coerced confessions, said such a thing could have happened to Skakel at the Elan School for teenagers with addiction problems.

Ofshe said he read a deposition and testimony from Skakel's murder trial and concluded that intimidation was used as a method of punishment at Elan.

Skakel's lawyers have said they would challenge trial lawyer Mickey Sherman's handling of testimony from former Elan School classmates in the trial, which ended with Skakel's conviction in 2002.

One classmate, Gregory Coleman, a convicted felon with a history of drug addiction and mental health issues, testified during a probable cause hearing that Skakel confessed the murder to him.

Under cross-examination Wednesday, Ofshe conceded that his theory did not apply to admissions Skakel made to Coleman and another Elan witness.

But Ofshe said the atmosphere at the school had led to a "shift" in Skakel's statements on the murder, from outright denying the crime to saying he didn't remember what happened. Ofshe, who worked on an exposé about a similar facility that won a Pulitzer Prize, used the words "intimidation" and "humiliation" to describe the atmosphere at the Elan school.

Last Wednesday, Constance Narayanan testified before Judge Thomas Bishop that while attending the Elan School — which no longer exists — she witnessed students "beating Michael alive" with a wooden paddle. They also forced him to wear signs saying, "I killed Martha Moxley," she said.

Ofshe's testimony came Monday during Day 5 of Skakel's habeas corpus hearing in Superior Court in Rockville, his latest attempt to get his conviction overturned.

Skakel was 41 when he was convicted of the 1975 murder of Martha Moxley. Moxley and Skakel were 15 — and neighbors — when she was beaten to death in the wealthy Belle Haven neighborhood in Greenwich.

The state Supreme Court has upheld Skakel's conviction, and the U.S. Supreme Court has declined to review the case. In October, Skakel. now 52, pleaded his innocence before the Connecticut Board of Pardons and Paroles but was denied release from prison.

Skakel is the nephew of Ethel Skakel Kennedy and Robert F Kennedy, the assassinated presidential candidate. His trial received widespread publicity because of his ties to the Kennedys.

On Monday, Skakel smiled, seemingly satisfied, at times — including in the afternoon when his lawyers continued their efforts to try to paint Sherman, his lawyer during the trial, as ineffective.

In spirited testimony, defense attorney Ron Murphy said Sherman had a conflict of interest because he did not disclose to Skakel that the state and federal governments had more than $400,000 in liens against the lawyer's property. Sherman knew about some of the liens before he wrote a letter to Skakel asking for money for his defense in 2001, Murphy said.

Murphy testified that Skakel's money could have been seized by the IRS, which placed most of the liens. It wasn't, he said. Sherman was sentenced in 2010 to a year and a day in federal prison for failing to pay about $420,000 in income taxes.

Defense attorney Michael Fitzpatrick said Sherman should have done more to find out about Coleman, who died before the trial. He said that includes calling lawyers who have represented him in the past and trying to glean information that's not covered by attorney-client privilege. Sherman did not do that, he said.

"Attorney Sherman had a duty to look under every rock," Fitzpatrick said.

Also testifying Monday was Leonard Levitt, a former freelance reporter who wrote one of four books on the case.

Levitt was asked if, for many years, he thought Thomas Skakel, Michael's older brother, was responsible for the murder.

"I still do," he said.

Press reports at the time of the trial said Thomas Skakel was one of the last people to see Moxley alive. He and Michael Skakel were considered to be intense rivals, including for Moxley's affection.